This project is probably the most ambitious so far, and can be expected to be very expensive. On the positive side, it is also capable of excellent performance, and can be tailored to suit your exact specifications. There are several different input modules....

These circuits could be used as the basis for Model Railroad DCC Boosters or PWM motor controllers. The first schematic is for a basic 3 Amp - DCC Booster using the LMD 18200 CMOS, H-Bridge. Included in the design is a 5Volt regulator that supplies....

H-Bridge This circuit drives small DC motors up to about 100 watts or 5 amps or 40 volts, whichever comes first. Using bigger parts could make it more powerful. Using a real H-bridge IC makes sense for this size of motor, but hobbyists love to do it....

The amplifier is capable of delivering around 1.5W into 8 ohm headphones, and 2.2W into 32 ohms - this is vastly more than will ever be needed in practice. The use of a 120 Ohm output resistor is recommended, as this is supposed to be the standard source....

This circuit was submitted by Graham Maynard from Newtownabbey, Northern Ireland. It has an exceptionally good high frequency response, as demonstrated by applying an 100kHz squarewave to the input. I have produced some response graphs using Tina Pro to....

Halloween is coming up and it's time to do some pranks. Everyone likes Halloween and I'm no exception. Every year me and my wife decorate the house with lot's of bugs, spider webs, creepy posters and of course lot's of Halloween candy. While making the....

On this page three adjustable notch filters configurations are shown . They can be used in your small pre-amp or amplifier project to filter out any HUM at 50 Hz ( European ) or 60Hz . By sustituting the capacitors values in the bridge other frequencies can....

Some Garmin GPS receivers are capable of running off external power ranging up to +32VDC or more, whereas others can only accept a maximum of +8VDC...

The first 5 circuits described in the following sections were reverse engineered from commercial HeNe power supplies. There may be errors in transcription as well as interpretation. In many cases, the transformer secondary voltage was not marked and....

With the advent of high speed HCMOS circuits, it is possible to build systems with clock rates of greater than 30 MHz. The familiar gate oscillator circuits used at low frequencies work well at higher frequencies and either LC or crystal resonators maybe....

A simple circuit, High-Pass filter, variable between frequencies 20HZ until 200HZ, useful in a lot of cases elaboration of sound signals. The regulation is achieved with the double potesometer 47K? and the frequency response in his two extreme places,....

is circuit was requested from an email. It will allow your car headlights to flash on and off at the same time or it will cause them to flash alternately. The circuit is based on the 555 timer. It is used in the astable mode. The 555 timer output will go....

This is a series regulator with Q900 being the control ele- ment, Q901 a driver, and Q902 an error amp. ZD900 forms the emitter reference voltage source. Since the generated high voltage and other voltages are linked by means of the magnetic field of....

In recent years more and more, have a tendency ket demanded higher reimbursement structures with lights and music lovers in general and manufacturers of tube amplifiers. The reason, in their view is that the sound of tubes is more sweet, how rich and....

The circuit below provides the horizontal drive voltage. The supply voltage on one end, +135 to +165, is made variable for the horizontal position control...

I leave it to the reader to supply their own power supply. I am using a supply from an old external SCSI drive. My cutter runs from the five volt supply and 25cm of nichrome wire pulls about 900mA or 4.5 watts. That is actually running a little hot and I....

The circuit in Figure 1 generates 100V from 25V. The circuit is a typical flyback regulator that uses a couple of well-established circuit techniques to handle the high voltage...

This document presents an overview of the hardware design of the Handy Cricket...

The MC74HC04 IC is a low cost CMOS Hex Inverter. I used this type mainly because, it is what I have, although you can use LS type but, with a little modification or exemptions....

The circuit uses fast transimpedance amps, "floated" at 70V. Two "virtual-zener" circuits step down the high-voltage signals for subsequent processing in a ground-referred differential-amplifier stage (Figure 1). The circuit drops exactly 65.58V dc with the....

This is a rather unusual QRP Power Amplifier design, with a wide frequency response; within three dB's from 300KHz to 30MHz. Overall gain is in the region of 16dB and the final output power may be well over four watts. The wide bandwidth is a result of the....

The Hot Springs tanks and circuit board should be mounted in a location that is free of ambient electro-magnetic fields. The input and output jacks are typically placed on a patch panel with other effect`s inputs and outputs. In use, the effects or aux send....

Modulation Monitor is a simple and useful circuit for hams. You can listen to on air transmission from your rig and be sure about the quality of the transmission. It requires no direct connection with the transmitter. In the prototype, headphones of 1K....

The LT®1510 current mode PWM battery charger is the simplest, most efficient solution for fast charging modern rechargeable batteries including lithium-ion (Li-Ion), nickelmetal- hydride (NiMH) and nickel-cadmium (NiCd) that require constant current....

This circuit is intended to control a heating system or central heating plan, keeping constant indoor temperature in spite of wide range changes in the outdoor one. Two sensors are needed: one placed outdoors, in order to sense the external temperature; the....

This is a circuit thich I originally included in my book, 22 Tested Transistor Projects, published by Babani Press in 1976 (ISBN 0 900162 63 S). It is one I had great fun with. It uses the PUT Complimentary Feedback Pair as a sensitive detector of changing....

Using a 12-bit-resolution analog-to-digital converter (ADC) does not necessarily mean your system will have 12-bit accuracy. Sometimes, much to the surprise and consternation of engineers, a data-acquisition system will exhibit much lower performance than....

The genesis for this hybrid electrostatic headphone amplifier occurred when I was in Hawaii on vacation, at a fancy hotel on Maui. Sitting at the bar on the beach, drinking "Blue Hawaiis," I drew the schematic for the amp on a placemat. The design is my....

This circuit is designed primarily for the situation where a hijacker forces the driver from the vehicle. If a door is opened while the ignition is switched on, the circuit will trip. After a few minutes delay - when the thief is at a safe distance - the....

The entire circuit is powered from a very simple regulated +-15V power supply, that is able to deliver about 2 A continuous duty, and at least 6 A on musical peaks. Two three-terminal regulators with power transistors wrapped around them do the regulating....